Conventionally, a vehicular device equipped to a vehicle has been designed and manufactured to adapt to a vehicle rank (automobile rank) of the vehicle. For example, in a case where a vehicle is equipped with an engine, a vehicular device is designed and manufactured exclusively to adapt to the feature of the engine, such as the number of cylinders and/or the displacement of the engine. In addition, a vehicular device is designed and manufactured exclusively to adapt to various categories of a vehicle, such as a vehicle rank including a popular car, a luxury car, a track, and/or a passenger car.
It is noted that, a vehicle having an electric motor as a power source emits a small noise when traveling or when being ready to travel. Accordingly, a person inside or outside the vehicle hardly sense that the vehicle is traveling or the vehicle is ready to travel. In consideration of this, a proposed vehicular device is configured to emit a specific sound to notify a person that a vehicle is traveling or a vehicle is ready to travel.
For example, JP-A-2005-343360 discloses a device configured to emit a predetermined alarm sound when a vehicle travels with an electric motor. The device of JP-A-2005-343360 employs a microcomputer to output the alarm sound. The microcomputer is equipped with a memory device for storing data of the alarm sound.
In the case of a conventional device designed and manufactured exclusive to a specific vehicle rank, as described above, one kind of such a conventional device cannot be adaptive to multiple vehicle ranks. Accordingly, such a conventional device is apt to require a high manufacturing cost. It is conceivable to input information representing a vehicle rank into a device when the device is equipped to a vehicle thereby to set an initial configuration of the device. In this case, nevertheless, the initial configuration requires an additional man power.
It is noted that, the device of JP-A-2005-343360 emits a constant alarm sound regardless of the vehicle rank of a vehicle. Accordingly, such a device may possibly cause a person inside or outside the vehicle to feel uncomfortable or unpleasant. Furthermore, the device of JP-A-2005-343360 emits the alarm sound different from a noise caused by actual traveling of the vehicle. Accordingly, such a device may possibly cause a person inside or outside the vehicle to feel uncomfortable or unpleasant.
The conventional configuration requires to secure a storage region in a microcomputer for storing data of a sound source. Processing of a sound at a frequency of several kilohertz imposes a high computation load to a microcomputer. Therefore, an exclusive electronic control device is required for processing such a high-frequency sound. Furthermore, in order to add a function for emitting an operation notification sound to a conventional electronic control unit, a microcomputer with high processing performance is required. As described above, in a conventional configuration, a large-scale device and a large number of circuit components are additionally required in order to produce an operation notification sound.